1
|
Ahmed M, Kayal E, Lavrov DV. Mitochondrial DNA of the Demosponge Acanthella acuta: Linear Architecture and Other Unique Features. Genome Biol Evol 2024; 16:evae168. [PMID: 39176446 PMCID: PMC11358620 DOI: 10.1093/gbe/evae168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 07/05/2024] [Accepted: 07/30/2024] [Indexed: 08/24/2024] Open
Abstract
While Acanthella acuta Schmidt 1862, a common demosponge found in the Mediterranean Sea and Atlantic Ocean, is morphologically similar to other sponges, its mitochondrial DNA (mtDNA) is unique within the class. In contrast to all other studied demosponges, the mtDNA of A. acuta is inferred to be linear and displays several unusual features such as inverted terminal repeats, group II introns in three mitochondrial genes, and two unique open reading frames (ORFs): one of which (ORF1535) combines a DNA polymerase domain with a DNA-directed RNA polymerase domain, while the second bears no discernible similarity to any reported sequences. The group II intron within the cox2 gene is the first such intron reported in an animal. Our phylogenetic analyses indicate that the cox1 intron is related to similar introns found in other demosponges, while the cox2 intron is likely not of animal origin. The two domains found within ORF1535 do not share a common origin and, along with the cox2 intron, were likely acquired by horizontal gene transfer. The findings of this paper open new avenues of exploration in the understanding of mtDNA linearization within Metazoa.
Collapse
Affiliation(s)
- Momin Ahmed
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Ehsan Kayal
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Dennis V Lavrov
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| |
Collapse
|
2
|
Liu X, Wu X, Tan H, Xie B, Deng Y. Large inverted repeats identified by intra-specific comparison of mitochondrial genomes provide insights into the evolution of Agrocybe aegerita. Comput Struct Biotechnol J 2020; 18:2424-2437. [PMID: 33005305 PMCID: PMC7508693 DOI: 10.1016/j.csbj.2020.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 11/29/2022] Open
Abstract
Genomic structure and content of Agrocybe aegerita mitochondrial DNA contain essential information regarding the evolution of this gourmet mushroom. In this study, eight isolates of A. aegerita were sequenced and assembled into complete mitochondrial genomes. The mtDNA of the isolate Ag0067 contained two genotypes, both of which were quadripartite architecture consisting of two identical inverted repeats, separated by a small single-copy region and a large single-copy region. The only difference was opposite directions of the small single-copy region. The mtDNAs ranged from 116,329 bp to 134,035 bp, harboring two large identical inverted repeats. Genes of plasmid-origin were present in regions flanked by inverted repeat ID2. Most of the core genes evolved at a relatively low rate, whereas five tRNA genes located in corresponding regions of Ag0002:1-14000 and Ag0002:50001-61000 showed higher diversity. A long fragment inversion (10 Kb) was suggested to have occurred during the differentiation of two main clades, leading to two different gene orders. The number and distribution of the introns varied greatly among the A. aegerita mtDNAs. Fast invasion of short insertions likely resulted in the diversity of introns as well as other non-coding regions, increasing the variation of the mtDNAs. We raised a model about the evolution of the large repeats to explain the unusual features of A. aegerita mtDNAs. This study constructed quadripartite architecture of A. aegerita mtDNAs analogous to chloroplast DNA, proposed an interconversion model of the divergent mitochondrial genotypes with large inverted repeats. The findings could increase our knowledge of fungal evolution.
Collapse
Affiliation(s)
- Xinrui Liu
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Xiaoping Wu
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Hao Tan
- Mushroom Research Center, Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610000, China
- School of Bioengineering, Jiangnan University, Wuxi 214062, China
| | - Baogui Xie
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Youjin Deng
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| |
Collapse
|
3
|
Kolesnikova AI, Putintseva YA, Simonov EP, Biriukov VV, Oreshkova NV, Pavlov IN, Sharov VV, Kuzmin DA, Anderson JB, Krutovsky KV. Mobile genetic elements explain size variation in the mitochondrial genomes of four closely-related Armillaria species. BMC Genomics 2019; 20:351. [PMID: 31068137 PMCID: PMC6506933 DOI: 10.1186/s12864-019-5732-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 04/24/2019] [Indexed: 12/03/2022] Open
Abstract
Background Species in the genus Armillaria (fungi, basidiomycota) are well-known as saprophytes and pathogens on plants. Many of them cause white-rot root disease in diverse woody plants worldwide. Mitochondrial genomes (mitogenomes) are widely used in evolutionary and population studies, but despite the importance and wide distribution of Armillaria, the complete mitogenomes have not previously been reported for this genus. Meanwhile, the well-supported phylogeny of Armillaria species provides an excellent framework in which to study variation in mitogenomes and how they have evolved over time. Results Here we completely sequenced, assembled, and annotated the circular mitogenomes of four species: A. borealis, A. gallica, A. sinapina, and A. solidipes (116,443, 98,896, 103,563, and 122,167 bp, respectively). The variation in mitogenome size can be explained by variable numbers of mobile genetic elements, introns, and plasmid-related sequences. Most Armillaria introns contained open reading frames (ORFs) that are related to homing endonucleases of the LAGLIDADG and GIY-YIG families. Insertions of mobile elements were also evident as fragments of plasmid-related sequences in Armillaria mitogenomes. We also found several truncated gene duplications in all four mitogenomes. Conclusions Our study showed that fungal mitogenomes have a high degree of variation in size, gene content, and genomic organization even among closely related species of Armillara. We suggest that mobile genetic elements invading introns and intergenic sequences in the Armillaria mitogenomes have played a significant role in shaping their genome structure. The mitogenome changes we describe here are consistent with widely accepted phylogenetic relationships among the four species. Electronic supplementary material The online version of this article (10.1186/s12864-019-5732-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anna I Kolesnikova
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia.,Laboratory of Genomic Research and Biotechnology, Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences", Krasnoyarsk, 660036, Russia
| | - Yuliya A Putintseva
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia
| | - Evgeniy P Simonov
- Laboratory of Genomic Research and Biotechnology, Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences", Krasnoyarsk, 660036, Russia.,Institute of Animal Systematics and Ecology, Siberian Branch of Russian Academy of Sciences, 630091, Novosibirsk, Russia
| | - Vladislav V Biriukov
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia.,Laboratory of Genomic Research and Biotechnology, Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences", Krasnoyarsk, 660036, Russia
| | - Natalya V Oreshkova
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia.,Laboratory of Genomic Research and Biotechnology, Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences", Krasnoyarsk, 660036, Russia.,Laboratory of Forest Genetics and Selection, V. N. Sukachev Institute of Forest, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk, 660036, Russia
| | - Igor N Pavlov
- Laboratory of Reforestation, Mycology and Plant Pathology, V. N. Sukachev Institute of Forest, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk, 660036, Russia
| | - Vadim V Sharov
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia.,Laboratory of Genomic Research and Biotechnology, Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences", Krasnoyarsk, 660036, Russia.,Department of High Performance Computing, Institute of Space and Information Technologies, Siberian Federal University, Krasnoyarsk, 660074, Russia
| | - Dmitry A Kuzmin
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia.,Department of High Performance Computing, Institute of Space and Information Technologies, Siberian Federal University, Krasnoyarsk, 660074, Russia
| | - James B Anderson
- Department of Biology, University of Toronto, Mississauga, ON, l5L 1C6, Canada
| | - Konstantin V Krutovsky
- Laboratory of Forest Genomics, Genome Research and Education Center, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, 660036, Russia. .,Department of Forest Genetics and Forest Tree Breeding, Georg-August University of Göttingen, 37077, Göttingen, Germany. .,Laboratory of Population Genetics, N. I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119333, Russia. .,Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843-2138, USA.
| |
Collapse
|
4
|
Kayal E, Bentlage B, Collins AG. Insights into the transcriptional and translational mechanisms of linear organellar chromosomes in the box jellyfish Alatina alata (Cnidaria: Medusozoa: Cubozoa). RNA Biol 2016; 13:799-809. [PMID: 27267414 DOI: 10.1080/15476286.2016.1194161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND In most animals, the mitochondrial genome is characterized by its small size, organization into a single circular molecule, and a relative conservation of the number of encoded genes. In box jellyfish (Cubozoa, Cnidaria), the mitochondrial genome is organized into 8 linear mito-chromosomes harboring between one and 4 genes each, including 2 extra protein-coding genes: mt-polB and orf314. Such an organization challenges the traditional view of mitochondrial DNA (mtDNA) expression in animals. In this study, we investigate the pattern of mitochondrial gene expression in the box jellyfish Alatina alata, as well as several key nuclear-encoded molecular pathways involved in the processing of mitochondrial gene transcription. RESULTS Read coverage of DNA-seq data is relatively uniform for all 8 mito-chromosomes, suggesting that each mito-chromosome is present in equimolar proportion in the mitochondrion. Comparison of DNA and RNA-seq based assemblies indicates that mito-chromosomes are transcribed into individual transcripts in which the beginning and ending are highly conserved. Expression levels for mt-polB and orf314 are similar to those of other mitochondrial-encoded genes, which provides further evidence for them having functional roles in the mitochondrion. Survey of the transcriptome suggests recognition of the mitochondrial tRNA-Met by the cytoplasmic aminoacyl-tRNA synthetase counterpart and C-to-U editing of the cytoplasmic tRNA-Trp after import into the mitochondrion. Moreover, several mitochondrial ribosomal proteins appear to be lost. CONCLUSIONS This study represents the first survey of mitochondrial gene expression of the linear multi-chromosomal mtDNA in box jellyfish (Cubozoa). Future exploration of small RNAs and the proteome of the mitochondrion will test the hypotheses presented herein.
Collapse
Affiliation(s)
- Ehsan Kayal
- a Department of Invertebrate Zoology , National Museum of Natural History, Smithsonian Institution , Washington DC , USA
| | - Bastian Bentlage
- a Department of Invertebrate Zoology , National Museum of Natural History, Smithsonian Institution , Washington DC , USA
| | - Allen G Collins
- a Department of Invertebrate Zoology , National Museum of Natural History, Smithsonian Institution , Washington DC , USA.,b National Systematics Laboratory of NOAA's Fisheries Service, National Museum of Natural History , Washington , DC , USA
| |
Collapse
|
5
|
Mardanov AV, Beletsky AV, Kadnikov VV, Ignatov AN, Ravin NV. The 203 kbp mitochondrial genome of the phytopathogenic fungus Sclerotinia borealis reveals multiple invasions of introns and genomic duplications. PLoS One 2014; 9:e107536. [PMID: 25216190 PMCID: PMC4162613 DOI: 10.1371/journal.pone.0107536] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 08/19/2014] [Indexed: 01/13/2023] Open
Abstract
Here we report the complete sequence of the mitochondrial (mt) genome of the necrotrophic phytopathogenic fungus Sclerotinia borealis, a member of the order Helotiales of Ascomycetes. The 203,051 bp long mtDNA of S. borealis represents one of the largest sequenced fungal mt genomes. The large size is mostly determined by the presence of mobile genetic elements, which include 61 introns. Introns contain a total of 125,394 bp, are scattered throughout the genome, and are found in 12 protein-coding genes and in the ribosomal RNA genes. Most introns contain complete or truncated ORFs that are related to homing endonucleases of the LAGLIDADG and GIY-YIG families. Integrations of mobile elements are also evidenced by the presence of two regions similar to fragments of inverton-like plasmids. Although duplications of some short genome regions, resulting in the appearance of truncated extra copies of genes, did occur, we found no evidences of extensive accumulation of repeat sequences accounting for mitochondrial genome size expansion in some other fungi. Comparisons of mtDNA of S. borealis with other members of the order Helotiales reveal considerable gene order conservation and a dynamic pattern of intron acquisition and loss during evolution. Our data are consistent with the hypothesis that horizontal DNA transfer has played a significant role in the evolution and size expansion of the S. borealis mt genome.
Collapse
Affiliation(s)
| | | | | | | | - Nikolai V. Ravin
- Centre “Bioengineering”, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
6
|
Milani L, Ghiselli F, Guerra D, Breton S, Passamonti M. A comparative analysis of mitochondrial ORFans: new clues on their origin and role in species with doubly uniparental inheritance of mitochondria. Genome Biol Evol 2013; 5:1408-34. [PMID: 23824218 PMCID: PMC3730352 DOI: 10.1093/gbe/evt101] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Despite numerous comparative mitochondrial genomics studies revealing that animal mitochondrial genomes are highly conserved in terms of gene content, supplementary genes are sometimes found, often arising from gene duplication. Mitochondrial ORFans (ORFs having no detectable homology and unknown function) were found in bivalve molluscs with Doubly Uniparental Inheritance (DUI) of mitochondria. In DUI animals, two mitochondrial lineages are present: one transmitted through females (F-type) and the other through males (M-type), each showing a specific and conserved ORF. The analysis of 34 mitochondrial major Unassigned Regions of Musculista senhousia F- and M-mtDNA allowed us to verify the presence of novel mitochondrial ORFs in this species and to compare them with ORFs from other species with ascertained DUI, with other bivalves and with animals showing new mitochondrial elements. Overall, 17 ORFans from nine species were analyzed for structure and function. Many clues suggest that the analyzed ORFans arose from endogenization of viral genes. The co-option of such novel genes by viral hosts may have determined some evolutionary aspects of host life cycle, possibly involving mitochondria. The structure similarity of DUI ORFans within evolutionary lineages may also indicate that they originated from independent events. If these novel ORFs are in some way linked to DUI establishment, a multiple origin of DUI has to be considered. These putative proteins may have a role in the maintenance of sperm mitochondria during embryo development, possibly masking them from the degradation processes that normally affect sperm mitochondria in species with strictly maternal inheritance.
Collapse
Affiliation(s)
- Liliana Milani
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali, University of Bologna, Bologna, Italy.
| | | | | | | | | |
Collapse
|
7
|
Férandon C, Xu J, Barroso G. The 135 kbp mitochondrial genome of Agaricus bisporus is the largest known eukaryotic reservoir of group I introns and plasmid-related sequences. Fungal Genet Biol 2013; 55:85-91. [DOI: 10.1016/j.fgb.2013.01.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 01/02/2013] [Accepted: 01/31/2013] [Indexed: 11/26/2022]
|
8
|
Xavier BB, Miao VPW, Jónsson ZO, Andrésson ÓS. Mitochondrial genomes from the lichenized fungi Peltigera membranacea and Peltigera malacea: features and phylogeny. Fungal Biol 2012; 116:802-14. [PMID: 22749167 DOI: 10.1016/j.funbio.2012.04.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 04/20/2012] [Accepted: 04/21/2012] [Indexed: 12/15/2022]
Abstract
Mitochondrial genomes from the fungal partners of two terricolous foliose lichen symbioses, Peltigera membranacea and Peltigera malacea, have been determined using metagenomic approaches, including RNA-seq. The roughly 63 kb genomes show all the major features found in other Pezizomycotina, such as unidirectional transcription, 14 conserved protein genes, genes for the two subunit rRNAs and for a set of 26 tRNAs used in translating the 62 amino acid codons. In one of the tRNAs a CAU anticodon is proposed to be modified, via the action of the nuclear-encoded enzyme, tRNA Ile lysidine synthase, so that it recognizes the codon AUA (Ile) instead of AUG (Met). The overall arrangements and sequences of the two circular genomes are similar, the major difference being the inversion and deterioration of a gene encoding a type B DNA polymerase. Both genomes encode the RNA component of RNAse P, a feature seldom found in ascomycetes. The difference in genome size from the minimal ascomycete mitochondrial genomes is largely due to 17 and 20 group I introns, respectively, most associated with homing endonucleases and all found within protein-coding genes and the gene encoding the large subunit rRNA. One new intron insertion point was found, and an unusually small exon of seven nucleotides (nt) was identified and verified by RNA sequencing. Comparative analysis of mitochondrion-encoded proteins places the Peltigera spp., representatives of the class Lecanoromycetes, close to Leotiomycetes, Dothidiomycetes, and Sordariomycetes, in contrast to phylogenies found using nuclear genes.
Collapse
Affiliation(s)
- Basil Britto Xavier
- Department of Life and Environmental Sciences, University of Iceland, 101 Reykjavík, Iceland
| | | | | | | |
Collapse
|
9
|
Kayal E, Bentlage B, Collins AG, Kayal M, Pirro S, Lavrov DV. Evolution of linear mitochondrial genomes in medusozoan cnidarians. Genome Biol Evol 2011; 4:1-12. [PMID: 22113796 PMCID: PMC3267393 DOI: 10.1093/gbe/evr123] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In nearly all animals, mitochondrial DNA (mtDNA) consists of a single circular molecule that encodes several subunits of the protein complexes involved in oxidative phosphorylation as well as part of the machinery for their expression. By contrast, mtDNA in species belonging to Medusozoa (one of the two major lineages in the phylum Cnidaria) comprises one to several linear molecules. Many questions remain on the ubiquity of linear mtDNA in medusozoans and the mechanisms responsible for its evolution, replication, and transcription. To address some of these questions, we determined the sequences of nearly complete linear mtDNA from 24 species representing all four medusozoan classes: Cubozoa, Hydrozoa, Scyphozoa, and Staurozoa. All newly determined medusozoan mitochondrial genomes harbor the 17 genes typical for cnidarians and map as linear molecules with a high degree of gene order conservation relative to the anthozoans. In addition, two open reading frames (ORFs), polB and ORF314, are identified in cubozoan, schyphozoan, staurozoan, and trachyline hydrozoan mtDNA. polB belongs to the B-type DNA polymerase gene family, while the product of ORF314 may act as a terminal protein that binds telomeres. We posit that these two ORFs are remnants of a linear plasmid that invaded the mitochondrial genomes of the last common ancestor of Medusozoa and are responsible for its linearity. Hydroidolinan hydrozoans have lost the two ORFs and instead have duplicated cox1 at each end of their mitochondrial chromosome(s). Fragmentation of mtDNA occurred independently in Cubozoa and Hydridae (Hydrozoa, Hydroidolina). Our broad sampling allows us to reconstruct the evolutionary history of linear mtDNA in medusozoans.
Collapse
Affiliation(s)
- Ehsan Kayal
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, USA.
| | | | | | | | | | | |
Collapse
|
10
|
Identification of four Entamoeba histolytica organellar DNA polymerases of the family B and cellular localization of the Ehodp1 gene and EhODP1 protein. J Biomed Biotechnol 2010; 2010:734898. [PMID: 20300437 PMCID: PMC2840583 DOI: 10.1155/2010/734898] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 12/15/2009] [Indexed: 11/20/2022] Open
Abstract
We report the identification of a family of four active genes (Ehodp1, Ehodp2, Ehodp3, and Ehodp4) encoding putative DNA polymerases in Entamoeba histolytica, the protozoan parasite responsible of human amoebiasis. The four Ehodp genes show similarity to DNA polymerases encoded in fungi and plant mitochondrial plasmids. EhODP polypeptides conserve the 3′-5′ exonuclease II and 5′-3′ polymerization domains, and they have the I, II, and III conserved boxes that characterize them as DNA polymerases of family B. Furthermore, we found in EhODP polymerases two novel A and B boxes, present also in DNA polymerases encoded in fungi mitochondrial plasmids. By in situ PCR, Ehodp1 gene was located in nuclei and in DNA-containing cytoplasmic structures. Additionally, using polyclonal antibodies against a recombinant rEhODP1-168 polypeptide, and confocal microscopy, EhODP1 was located in cytoplasmic DNA-containing structures.
Collapse
|
11
|
Ferandon C, Chatel SEK, Castandet B, Castroviejo M, Barroso G. The Agrocybe aegerita mitochondrial genome contains two inverted repeats of the nad4 gene arisen by duplication on both sides of a linear plasmid integration site. Fungal Genet Biol 2008; 45:292-301. [DOI: 10.1016/j.fgb.2007.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Revised: 09/24/2007] [Accepted: 10/17/2007] [Indexed: 11/25/2022]
|
12
|
Signorovitch AY, Buss LW, Dellaporta SL. Comparative genomics of large mitochondria in placozoans. PLoS Genet 2007; 3:e13. [PMID: 17222063 PMCID: PMC1781491 DOI: 10.1371/journal.pgen.0030013] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Accepted: 12/05/2006] [Indexed: 11/22/2022] Open
Abstract
The first sequenced mitochondrial genome of a placozoan, Trichoplax adhaerens, challenged the conventional wisdom that a compact mitochondrial genome is a common feature among all animals. Three additional placozoan mitochondrial genomes representing highly divergent clades have been sequenced to determine whether the large Trichoplax mtDNA is a shared feature among members of the phylum Placozoa or a uniquely derived condition. All three mitochondrial genomes were found to be very large, 32- to 37-kb, circular molecules, having the typical 12 respiratory chain genes, 24 tRNAs, rnS, and rnL. They share with the Trichoplax mitochondrial genome the absence of atp8, atp9, and all ribosomal protein genes, the presence of several cox1 introns, and a large open reading frame containing an intron group I LAGLIDADG endonuclease domain. The differences in mtDNA size within Placozoa are due to variation in intergenic spacer regions and the presence or absence of long open reading frames of unknown function. Phylogenetic analyses of the 12 respiratory chain genes support the monophyly of Placozoa. The similarities in composition and structure between the three mitochondrial genomes reported here and that of Trichoplax's mtDNA suggest that their uncompacted state is a shared ancestral feature to other nonmetazoans while their gene content is a derived feature shared only among the Metazoa.
Collapse
Affiliation(s)
- Ana Y Signorovitch
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
| | - Leo W Buss
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut, United States of America
| | - Stephen L Dellaporta
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| |
Collapse
|
13
|
Shao Z, Graf S, Chaga OY, Lavrov DV. Mitochondrial genome of the moon jelly Aurelia aurita (Cnidaria, Scyphozoa): A linear DNA molecule encoding a putative DNA-dependent DNA polymerase. Gene 2006; 381:92-101. [PMID: 16945488 DOI: 10.1016/j.gene.2006.06.021] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 06/20/2006] [Accepted: 06/23/2006] [Indexed: 11/17/2022]
Abstract
The 16,937-nuceotide sequence of the linear mitochondrial DNA (mt-DNA) molecule of the moon jelly Aurelia aurita (Cnidaria, Scyphozoa) - the first mtDNA sequence from the class Scypozoa and the first sequence of a linear mtDNA from Metazoa - has been determined. This sequence contains genes for 13 energy pathway proteins, small and large subunit rRNAs, and methionine and tryptophan tRNAs. In addition, two open reading frames of 324 and 969 base pairs in length have been found. The deduced amino-acid sequence of one of them, ORF969, displays extensive sequence similarity with the polymerase [but not the exonuclease] domain of family B DNA polymerases, and this ORF has been tentatively identified as dnab. This is the first report of dnab in animal mtDNA. The genes in A. aurita mtDNA are arranged in two clusters with opposite transcriptional polarities; transcription proceeding toward the ends of the molecule. The determined sequences at the ends of the molecule are nearly identical but inverted and lack any obvious potential secondary structures or telomere-like repeat elements. The acquisition of mitochondrial genomic data for the second class of Cnidaria allows us to reconstruct characteristic features of mitochondrial evolution in this animal phylum.
Collapse
Affiliation(s)
- Zhiyong Shao
- Interdepartmental Genetics Graduate Program, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | |
Collapse
|